This invention relates to cargo handling mechanisms such as those used in aircraft, and more particularly relates to a powered restraint for preventing cargo from rolling back out of the cargo hold of an aircraft once it has been loaded.
Typically, cargo is loaded into an aircraft cargo hold in containers specially constructed to utilize as much as possible the available space in the cargo hold. The cargo deck typically is comprised of a plurality of ball mats containing roller balls to ease the passage of cargo containers over the deck. While the use of such ball mats greatly enhances the ability to rapidly move cargo containers into the aircraft hold, it also makes it easier for those containers to roll back out of the cargo hold if the cargo deck is not level. It is necessary therefore to provide some type of restraining mechanism, preferably in the door of the cargo hold, which permits passage of cargo into the hold but prevents it from rolling back out of the hold.
A device for restraining cargo once it has been loaded into the cargo hold of an aircraft is described in U.S. Pat. No. 3,698,679 to Lang et al., issued Oct. 17, 1972 and incorporated herein by reference. The restraint of the Lang et al. patent includes a lip member which, in normal operation, extends above the level of the cargo floor and engages the lower edge of cargo containers passing into the hold. The lip member yields to the cargo containers passing into the cargo hold, such that the container forces the lip member below the level of the cargo floor, permitting the container to enter the hold. However, the lip member does not yield in the opposite direction. Therefore, cargo abutting the lip member from within the hold is maintained in the cargo hold by the lip member. When it is desired to unload the aircraft, the lip member of the Lang et al. cargo restraint can be manually placed in a position below the level of the cargo deck, thereby permitting cargo to pass out through the door of the cargo hold.
The Lang et al. restraint is manually operable and requires that the load master or his assistants move to the restraint in order to release it for cargo unloading. Also, if the cargo containers are to be removed one at a time it is necessary after each container passes over the restraint mechanism to manually reset the restraint to raise the lip member to its normal extended position to prevent the remaining cargo containers from exiting the cargo hold prematurely.
It is therefore an object of the present invention to provide a cargo restraint that extends into the path of travel of cargo entering and exiting a cargo hold to prevent passage of cargo in one direction and allow passage of cargo in a second and opposite direction, which restraint can be retracted out of the cargo path by a powered means.
It is a further object of this invention to provide such a cargo restraint which can be extended and retracted from a remote location.
It is another object of this invention to provide a cargo restraint of the type described above which operates in a limited space envelope.
It is an object of this invention to provide a cargo restraint which has a manual override to enable an operator to manually move the restraint between its retracted and extended positions in case the powered means is inoperative to permit the continued loading and unloading of cargo.